Selling, general and administrative expenses

6 Months Ended

Jun. 30, 2017

Selling General And Administrative Expenses [Abstract]

Selling, general and administrative expenses

20. Selling, general and administrative expenses

Selling, general and administrative expenses consist of the following:

	Three months ended June 30,				Six months ended June 30,
	2016		2017		2016		2017
Personnel expenses	$	117,857	$	122,686	$	226,257	$	245,255
Operational expenses		45,158		42,867		94,736		78,680
Depreciation and amortization		2,182		2,348		4,353		4,824
	$	165,197	$	167,901	$	325,346	$	328,759